That scene had me in stitches the first few times I saw it. We're used to a calm, mild mannered Vito and suddenly *WHAM*, that big outburst. Both Johnny and Tom are laughing during it all. I think Vito's intent there was to shut down Johnny's whining funk and to get his full attention. His outburst was an attention getter, and it definitely succeeded. Vito was then able to communicate man to man with Johnny, not man to whiny crybaby.

Ever try to talk calmly to someone who's on a roll of whining? You might as well be talking to a wall.